bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2020‒08‒16
sixteen papers selected by
Oltea Sampetrean
Keio University

  1. Cancer Cell. 2020 Jul 30. pii: S1535-6108(20)30369-X. [Epub ahead of print]
    Chung C, Sweha SR, Pratt D, Tamrazi B, Panwalkar P, Banda A, Bayliss J, Hawes D, Yang F, Lee HJ, Shan M, Cieslik M, Qin T, Werner CK, Wahl DR, Lyssiotis CA, Bian Z, Shotwell JB, Yadav VN, Koschmann C, Chinnaiyan AM, Blüml S, Judkins AR, Venneti S.
      H3K27M diffuse intrinsic pontine gliomas (DIPGs) are fatal and lack treatments. They mainly harbor H3.3K27M mutations resulting in H3K27me3 reduction. Integrated analysis in H3.3K27M cells, tumors, and in vivo imaging in patients showed enhanced glycolysis, glutaminolysis, and tricarboxylic acid cycle metabolism with high alpha-ketoglutarate (α-KG) production. Glucose and/or glutamine-derived α-KG maintained low H3K27me3 in H3.3K27M cells, and inhibition of key enzymes in glycolysis or glutaminolysis increased H3K27me3, altered chromatin accessibility, and prolonged survival in animal models. Previous studies have shown that mutant isocitrate-dehydrogenase (mIDH)1/2 glioma cells convert α-KG to D-2-hydroxyglutarate (D-2HG) to increase H3K27me3. Here, we show that H3K27M and IDH1 mutations are mutually exclusive and experimentally synthetic lethal. Overall, we demonstrate that H3.3K27M and mIDH1 hijack a conserved and critical metabolic pathway in opposing ways to maintain their preferred epigenetic state. Consequently, interruption of this metabolic/epigenetic pathway showed potent efficacy in preclinical models, suggesting key therapeutic targets for much needed treatments.
    Keywords:  D-2HG; DIPG; H3K27me3; IDH mutation; epigenetics; glutaminolysis; glycolysis; histone methylation; histone mutation; metabolism; α-KG
  2. Neuro Oncol. 2020 Aug 13. pii: noaa189. [Epub ahead of print]
    Daniel AGS, Park KY, Roland JL, Dierker D, Gross J, Humphries JB, Hacker CD, Snyder AZ, Shimony JS, Leuthardt EC.
      BACKGROUND: Glioblastoma (GBM; WHO grade IV) assumes a variable appearance on magnetic resonance imaging owing to heterogeneous proliferation and infiltration of its cells. As a result, the neurovascular units responsible for functional connectivity (FC) may exist within gross tumor boundaries, albeit with altered magnitude. Therefore, we hypothesize that the strength of functional connectivity within GBMs is predictive of overall survival.METHODS: We used pre-defined FC regions of interest (ROIs) in denovo GBM patients to characterize the presence of within-tumor FC observable via resting-state fMRI and its relationship to survival outcomes.
    RESULTS: 57 GBM patients (mean age 57.8 ± 13.9 years) were analyzed. Functionally connected voxels, not identifiable on conventional structural images, can be routinely found within the tumor mass and was not significantly correlated to tumor size. In patients with known survival times (n = 31), higher intra-network FC strength within GBM tumors was associated with better overall survival even after accounting for clinical and demographic covariates.
    CONCLUSIONS: These findings suggest the possibility that functionally intact regions may persist within GBMs and that the extent to which FC is maintained may carry prognostic value and inform treatment planning.
    Keywords:  functional MRI; functional connectivity; glioblastoma; glioma; resting state
  3. Clin Cancer Res. 2020 Aug 11. pii: clincanres.1065.2020. [Epub ahead of print]
    Wildes TJ, Dyson KA, Francis CP, Wummer BM, Yang C, Yegorov O, Shin D, Grippin AJ, DiVita-Dean B, Abraham RS, Pham CD, Moore G, Kuizon C, Mitchell DA, Flores CT.
      PURPOSE: Immunotherapy is remarkably effective, yet tumor escape is common. It remains unclear how brain tumors escape immunotherapy and how to overcome this immune escape.EXPERIMENTAL DESIGN: We studied KR158B-luc glioma-bearing mice during treatment with adoptive cellular therapy (ACT) with polyclonal tumor-specific T cells. We tested the immunogenicity of primary and escaped tumors using T cell restimulation assays. We used flow cytometry and RNA profiling of whole tumors to further define escape mechanisms. To treat immune-escaped tumors, we generated escape variant-specific T cells through the use of escape variant total tumor RNA and administered these cells as ACT. Additionally, PD-1 checkpoint blockade was studied in combination with ACT.
    RESULTS: Escape mechanisms included a shift in immunogenic tumor antigens, downregulation of major histocompatibility complex (MHC) class I, and upregulation of checkpoint molecules. Polyclonal T cells specific for escape variants displayed greater recognition of escaped tumors than primary tumors. When administered as ACT, these T cells prolonged median survival of escape variant-bearing mice by 60%. The rational combination of ACT with PD-1 blockade prolonged median survival of escape variant glioma-bearing mice by 110% and was dependent upon NK cells and T cells.
    CONCLUSIONS: These findings suggest that the immune landscape of brain tumors are markedly different post-immunotherapy yet can still be targeted with immunotherapy.
  4. Exp Mol Med. 2020 Aug 12.
    Ciechomska IA, Gielniewski B, Wojtas B, Kaminska B, Mieczkowski J.
      Accumulating evidence suggests that glioma stem cells (GSCs), which are rare cells characterized by pluripotency and self-renewal ability, are responsible for glioblastoma (GBM) propagation, recurrence and resistance to therapies. Bone morphogenic proteins (BMPs) induce GSC differentiation, which leads to elimination of GSCs and sensitization of glioma to chemotherapeutics. Alterations in the epidermal growth factor receptor (EGFR) gene are detected in more than half of GBMs; however, the role of EGFR in the chemoresistance of GSCs remains unknown. Here, we examined whether EGFR signaling affects BMP4-induced differentiation of GSCs and their response to the alkylating drug temozolomide (TMZ). We show that BMP4 triggers the SMAD signaling cascade in GSCs independent of the EGFR level. BMP4 downregulated the levels of pluripotency markers (SOX2 and OLIG2) with a concomitant induction of an astrocytic marker (GFAP) and a neuronal marker (β-Tubulin III). However, GSCs with different EGFR levels responded differently to treatments. BMP4-induced differentiation did not enhance sensitivity to TMZ in EGFRlow GSCs, in contrast to EGFRhigh GSCs, which underwent apoptosis. We then identified differences in cell cycle regulation. In EGFRlow cells, BMP4-triggered G1 cell cycle arrest which was not detected in EGFRhigh cells. RNA-seq profiles further highlighted transcriptomic alterations and distinct processes characterizing EGFR-dependent responses in the course of BMP4-induced differentiation. We found that the control of BIM (the pro-apoptotic BCL-2 family protein) by the AKT/FOXO3a axis only operated in BMP4-differentiated EGFRhigh cells upon TMZ treatment.
  5. Expert Opin Drug Deliv. 2020 Aug 13.
    Gallego L, Ceña V.
      INTRODUCTION: Glioblastoma multiforme is the most common and the most aggressive primary brain tumor, with a median survival of 14 months. This dismal prognostic has turned research towards nanomedicine as a new therapeutic approach that can deliver therapeutic compounds to GBM.AREAS COVERED: The review covers recent advances in targeted delivery of therapeutic compounds to glioblastoma tumors. To reach the tumors, nanocarriers and their cargo should cross the Blood-Brain Barrier (BBB) standing between the blood stream and the tumor. For that purpose, different peptides to facilitate BBB crossing have been added to the nanoparticles. As result, an increase in BBB crossing was observed. Other significant effort has been devoted to selectively target direct the nanocarrier and its cargo to GBM tumors. Once again, targeting peptides have been used.
    EXPERT OPINION: Besides significant advances, a more successful design of nanocarriers for efficient BBB crossing and delivery of diagnostic and/or therapeutic molecules to CNS will be needed to achieve efficient nanomedicine-based therapeutics for glioblastoma. This will require a significant effort improving chemical architecture of nanocarriers, identifying the critical design parameters that might play a key role facilitating both BBB crossing and GBM selective targeting.
    Keywords:  Blood-Brain-Barrier; cancer; glioblastoma; miRNA; nanoparticle; siRNA; targeting peptide
  6. Neurooncol Adv. 2020 Jan-Dec;2(1):2(1): vdaa081
    Rezk R, Jia BZ, Wendler A, Dimov I, Watts C, Markaki AE, Franze K, Kabla AJ.
      Background: Glioblastoma (GBM) is a highly aggressive incurable brain tumor. The main cause of mortality in GBM patients is the invasive rim of cells migrating away from the main tumor mass and invading healthy parts of the brain. Although the motion is driven by forces, our current understanding of the physical factors involved in glioma infiltration remains limited. This study aims to investigate the adhesion properties within and between patients' tumors on a cellular level and test whether these properties correlate with cell migration.Methods: Six tissue samples were taken from spatially separated sections during 5-aminolevulinic acid (5-ALA) fluorescence-guided surgery. Navigated biopsy samples were collected from strongly fluorescent tumor cores, a weak fluorescent tumor rim, and nonfluorescent tumor margins. A microfluidics device was built to induce controlled shear forces to detach cells from monolayer cultures. Cells were cultured on low modulus polydimethylsiloxane representative of the stiffness of brain tissue. Cell migration and morphology were then obtained using time-lapse microscopy.
    Results: GBM cell populations from different tumor fractions of the same patient exhibited different migratory and adhesive behaviors. These differences were associated with sampling location and amount of 5-ALA fluorescence. Cells derived from weak- and nonfluorescent tumor tissue were smaller, adhered less well, and migrated quicker than cells derived from strongly fluorescent tumor mass.
    Conclusions: GBM tumors are biomechanically heterogeneous. Selecting multiple populations and broad location sampling are therefore important to consider for drug testing.
    Keywords:  cell migration; cell-matrix adhesion; glioblastoma
  7. iScience. 2020 Jul 29. pii: S2589-0042(20)30610-6. [Epub ahead of print]23(8): 101420
    Zeng A, Wei Z, Rabinovsky R, Jun HJ, El Fatimy R, Deforzh E, Arora R, Yao Y, Yao S, Yan W, Uhlmann EJ, Charest A, You Y, Krichevsky AM.
      Glioblastoma (GBM) may arise from astrocytes through a multistep process involving a progressive accumulation of mutations. We explored whether GBM-derived extracellular vesicles (EVs) may facilitate neoplastic transformation and malignant growth of astrocytes. We utilized conditioned media (CM) of cultured glioma cells, its sequential filtration, diverse cell-based assays, RNA sequencing, and metabolic assays to compare the effects of EV-containing and EV-depleted CM. GBM EVs facilitated the neoplastic growth of pre-transformed astrocytes but not normal human or mouse astrocytes. They induced proliferation, self-renewal, and colony formation of pre-transformed astrocytes and enhanced astrocytoma growth in a mouse allograft model. GBM EVs appear to reprogram astrocyte metabolism by inducing a shift in gene expression that may be partly associated with EV-mediated transfer of full-length mRNAs encoding ribosomal proteins, oxidative phosphorylation, and glycolytic factors. Our study suggests an EV/extracellular RNA (exRNA)-mediated mechanism that contributes to astrocyte transformation via metabolic reprograming and implicates horizontal mRNA transfer.
    Keywords:  Biological Sciences; Cancer; Cell Biology
  8. Mol Cancer Ther. 2020 Aug 12. pii: molcanther.0095.2020. [Epub ahead of print]
    Werner CK, Nna UJ, Sun H, Wilder-Romans K, Dresser J, Kothari AU, Zhou W, Yao Y, Rao A, Stallard S, Koschmann C, Bor T, Debinski W, Hegedus AM, Morgan MA, Venneti S, Baskin-Bey E, Spratt DE, Colman H, Sarkaria JN, Chinnaiyan AM, Eisner JR, Speers C, Lawrence TS, Strowd RE, Wahl DR.
      New approaches are needed to overcome intrinsic therapy resistance in glioblastoma (GBM). Because GBMs exhibit sexual dimorphism and are reported to express steroid hormone receptors, we reasoned that signaling through the androgen receptor (AR) could mediate therapy resistance in GBM, much as it does in AR-positive prostate and breast cancers. We found that nearly half of GBM cell lines, patient-derived xenografts and human tumors expressed AR at the transcript and protein level-with expression levels overlapping those of primary prostate cancer. Analysis of gene expression datasets also revealed that AR expression is higher in GBM patient samples than normal brain tissue. Multiple clinical-grade antiandrogens slowed the growth of and radiosensitized AR-positive GBM cell lines and patient-derived xenografts in vitro and in vivo. Antiandrogens blocked the ability of AR-positive GBM patient-derived xenografts to engage adaptive transcriptional programs following radiation and slowed the repair of radiation-induced DNA damage. These results suggest that combining blood-brain barrier permeable antiandrogens with radiation may have promise for patients with AR-positive GBMs.
  9. Neuro Oncol. 2020 Aug 08. pii: noaa185. [Epub ahead of print]
    Fults DW.
  10. Cancer Metab. 2020 ;8 9
    Oizel K, Yang C, Renoult O, Gautier F, Do QN, Joalland N, Gao X, Ko B, Vallette F, Ge WP, Paris F, DeBerardinis RJ, Pecqueur C.
      Background: Glioblastoma (GBM) are highly heterogeneous on the cellular and molecular basis. It has been proposed that glutamine metabolism of primary cells established from human tumors discriminates aggressive mesenchymal GBM subtype to other subtypes.Methods: To study glutamine metabolism in vivo, we used a human orthotopic mouse model for GBM. Tumors evolving from the implanted primary GBM cells expressing different molecular signatures were analyzed using mass spectrometry for their metabolite pools and enrichment in carbon 13 (13C) after 13C-glutamine infusion.
    Results: Our results showed that mesenchymal GBM tumors displayed increased glutamine uptake and utilization compared to both control brain tissue and other GBM subtypes. Furthermore, both glutamine synthetase and transglutaminase-2 were expressed accordingly to GBM metabolic phenotypes.
    Conclusion: Thus, our results outline the specific enhanced glutamine flux in vivo of the aggressive mesenchymal GBM subtype.
    Keywords:  Glioblastoma; Glutamine; Human primary cells; Mesenchymal; Metabolism; Molecular subtype; Orthotopic model
  11. Neuro Oncol. 2020 Aug 12. pii: noaa197. [Epub ahead of print]
    Tran AN, Horbinski C.
  12. Nucleic Acids Res. 2020 Aug 14. pii: gkaa669. [Epub ahead of print]
    Chien JC, Tabet E, Pinkham K, da Hora CC, Chang JC, Lin S, Badr CE, Lai CP.
      Tracking DNA double strand break (DSB) repair is paramount for the understanding and therapeutic development of various diseases including cancers. Herein, we describe a multiplexed bioluminescent repair reporter (BLRR) for non-invasive monitoring of DSB repair pathways in living cells and animals. The BLRR approach employs secreted Gaussia and Vargula luciferases to simultaneously detect homology-directed repair (HDR) and non-homologous end joining (NHEJ), respectively. BLRR data are consistent with next-generation sequencing results for reporting HDR (R2 = 0.9722) and NHEJ (R2 = 0.919) events. Moreover, BLRR analysis allows longitudinal tracking of HDR and NHEJ activities in cells, and enables detection of DSB repairs in xenografted tumours in vivo. Using the BLRR system, we observed a significant difference in the efficiency of CRISPR/Cas9-mediated editing with guide RNAs only 1-10 bp apart. Moreover, BLRR analysis detected altered dynamics for DSB repair induced by small-molecule modulators. Finally, we discovered HDR-suppressing functions of anticancer cardiac glycosides in human glioblastomas and glioma cancer stem-like cells via inhibition of DNA repair protein RAD51 homolog 1 (RAD51). The BLRR method provides a highly sensitive platform to simultaneously and longitudinally track HDR and NHEJ dynamics that is sufficiently versatile for elucidating the physiology and therapeutic development of DSB repair.
  13. Neurooncol Adv. 2020 Jan-Dec;2(1):2(1): vdaa083
    Dekker LJM, Kannegieter NM, Haerkens F, Toth E, Kros JM, Steenhoff Hov DA, Fillebeen J, Verschuren L, Leenstra S, Ressa A, Luider TM.
      Background: Despite maximal therapy with surgery, chemotherapy, and radiotherapy, glioblastoma (GBM) patients have a median survival of only 15 months. Almost all patients inevitably experience symptomatic tumor recurrence. A hallmark of this tumor type is the large heterogeneity between patients and within tumors itself which relates to the failure of standardized tumor treatment. In this study, tissue samples of paired primary and recurrent GBM tumors were investigated to identify individual factors related to tumor progression.Methods: Paired primary and recurrent GBM tumor tissues from 8 patients were investigated with a multiomics approach using transcriptomics, proteomics, and phosphoproteomics.
    Results: In the studied patient cohort, large variations between and within patients are observed for all omics analyses. A few pathways affected at the different omics levels partly overlapped if patients are analyzed at the individual level, such as synaptogenesis (containing the SNARE complex) and cholesterol metabolism. Phosphoproteomics revealed increased STMN1(S38) phosphorylation as part of ERBB4 signaling. A pathway tool has been developed to visualize and compare different omics datasets per patient and showed potential therapeutic drugs, such as abobotulinumtoxinA (synaptogenesis) and afatinib (ERBB4 signaling). Afatinib is currently in clinical trials for GBM.
    Conclusions: A large variation on all omics levels exists between and within GBM patients. Therefore, it will be rather unlikely to find a drug treatment that would fit all patients. Instead, a multiomics approach offers the potential to identify affected pathways on the individual patient level and select treatment options.
    Keywords:  glioblastoma; multiomics; phosphoproteomics; transcriptomics; tumor progression
  14. Int J Mol Sci. 2020 Aug 06. pii: E5631. [Epub ahead of print]21(16):
    Valtorta S, Salvatore D, Rainone P, Belloli S, Bertoli G, Moresco RM.
      This review highlights the importance and the complexity of tumour biology and microenvironment in the progression and therapy resistance of glioma. Specific gene mutations, the possible functions of several non-coding microRNAs and the intra-tumour and inter-tumour heterogeneity of cell types contribute to limit the efficacy of the actual therapeutic options. In this scenario, identification of molecular biomarkers of response and the use of multimodal in vivo imaging and in particular the Positron Emission Tomography (PET) based molecular approach, can help identifying glioma features and the modifications occurring during therapy at a regional level. Indeed, a better understanding of tumor heterogeneity and the development of diagnostic procedures can favor the identification of a cluster of patients for personalized medicine in order to improve the survival and their quality of life.
    Keywords:  PET; cell heterogeneity; glioma; miRNA; molecular imaging; predictive biomarkers; prognostic biomarkers; therapy resistance; tumor-microenvironment
  15. J Med Chem. 2020 Aug 11.
    Smil D, Wong JF, Williams E, Adamson R, Howarth A, McLeod D, Mamai A, Kim S, Wilson B, Kiyota T, Aman A, Owen J, Poda G, Horiuchi K, Kuznetsova E, Ma H, Hamblin JN, Cramp S, Roberts O, Edwards AM, Uehling D, Al-Awar R, Bullock AN, O'Meara J, Isaac M.
      There are currently no effective chemotherapeutic drugs approved for the treatment of diffuse intrinsic pontine glioma (DIPG), an aggressive pediatric cancer resident in the pons region of the brainstem. Radiation therapy is beneficial but not curative, with the condition being uniformly fatal. Analysis of the genomic landscape surrounding DIPG has revealed that activin receptor-like kinase-2 (ALK2) constitutes a potential target for therapeutic intervention given its dysregulation in the disease. We adopted an open science approach to develop a series of potent, selective, orally bioavailable, and brain penetrant ALK2 inhibitors based on lead compound LDN-214117. Modest structural changes to the C-3, C-4, and C-5 position substituents of the core pyridine ring afforded compounds M4K2009, M4K2117, and M4K2163, each with a superior potency, selectivity, and/or blood-brain barrier (BBB) penetration profile. Robust in vivo pharmacokinetic (PK) properties and tolerability mark these inhibitors as advanced pre-clinical compounds suitable for further development and evaluation in orthotopic models of DIPG.